The former Beatle recorded a voice message that was part of a text-to-call operation for Bennett’s Voices Against Violence campaign. McCartney and others encouraged Americans to send a text, which led to the singer’s message and connected the caller to his or her local Senate office after providing a zip code.

But the Senate rejected a bipartisan attempt to ban assault weapons Wednesday, one of their leading answers to December’s slayings of 20 children and six aides at an elementary in Newtown, Conn. The 54-46 vote fell along party lines, with most Democrats supporting the legislation and most Republicans rejecting it.

Bennett, 86, tweeted after the failed vote: “We will not stop until our voices are heard.”

Families of Newton victims and others affected by gun violence have been lobbying lawmakers and appearing at news conferences.